Antistatic and dyeable thermoplastic molding compositions and shaped articles of polyolefins

ABSTRACT

Antistatic polyolefin molding compositions and articles containing 0.1 - 5.0% by weight, based on the polyolefin, of one or more compounds of the formula:   WHEREIN R1 and R2 both are alkyl or alkenyl of 6-25 carbon atoms.

. United States Patent 1191 Ruter et al. 1*June 28, 1974 ANTlSTATlC AND DYEABLE [56] References Cited THERMOPLASTIC MOLDING UNITED STATES PATEN'l-S COMPOSITIONS AND SHAPED ARTICLES 3,70l,765 10/1972 Mugosch et al. 260/949 on 0F POLYOLEFINS 3,708,464 2/1973 Rombusch et a1 200/949 GB Inventors: Jtirn Riiter; Karl-Heinz Magosch;

Konrad Rombusch, all of Marl; Ursula Eichers, Recklinghausen, all of Germany Assigneez, Chemische Werke Huls Aktiengesellschaft, Marl, Germany Notice: The portion of the term of this patent subsequent to Oct. 31, 1989, has been disclaimed. 4

Filed: Sept. 29, 1971 Appl. No.: 184,938

F oreign Application Priority Data Field of Search 260/882 S, 93.7, 949GB Primary Examiner-loseph L. Schafer Assistant ExaminerEdward J. Smith Attorney, Agent, or Firm-Millen, Raptes & White [5 7] ABSTRACT Antistatic polyolefin molding compositions and articles containing 0.1 5.0% by weight, based on the polyolefin, of one or more compounds of the formula:

N-CH:

wherein R and R both are alkyl or alkenyl of 6-25 carbon atoms.

16 Claims, No Drawings MOLDING COMPOSITIONS AND SHAPED ARTICLES OF POLYOLEFINS BACKGROUND OF THE INVENTION This invention relates to antistatic and dye-absorbing thermoplastic molding compositions and shaped articlcs of polyolefins containing certain nitrogenous additives.

As is known, polyolefin products have a strong tendency to attract dust during storage and use due to electrostatic charging, which greatly diminishes their usefulness. 7

Various means have been suggested to overcome these difficulties. Thus, the surfaces of the polyethylene articles can be coated with a composition which reduces electrostatic charging. However, such processes usually have the disadvantage that the effectiveness is lost as soon as the antistatic coating is worn by use or cleaning. A more prolonged effect is attained by incorporating the antistatic additive into the polymeric material and producing shaped articles from these mix tures. Among these additives are, for example, quaternary ammonium salts, polyalkylene glycols and polyalkylene glycol esters.

Still better properties are achieved with oxyethylates of alkanols and alkylaryl phenols (Belgian Pat. 536,623 and British Pat. 73l,728). However, these compounds tend to bloom onto the surface when incorporated into the synthetic resin in an amount sufficient to achieve a satisfactory effect.

A further increase in antistatic effectiveness can be obtained employing nitrogen-containing compounds, such as, for example, amides and aminocarboxylic acid derivatives (French Pats. 1,377,803 808), oxazolines,

and imidazolines-and, to a still greater extent, with alkylamines (Belgian Pats. 655,182 and 655,183), especially oxyethylates of alkylamines (Belgian Pat. 645,800; French Pats. 1,345,827 and l,322,626; German Published Application DAS 1,228,056), the bishydroxyethyl derivatives being the most effective antistatics of all those described heretofore. However, these compounds often have the disadvantage that, in the first few days after the manufacture of the molded polyolefin article, film, filament or fiber, the additive does not immediately achieve its full antistatic effectiveness. The result is that the electrostatic charge which develops during processing and which generally is very high, for example. during separation from the mold in injection molding processes, cannot dissipate immediately, so that, within a few days, the molded articles become unattractive due to dust attraction. The situation is aggravated by the large amount of dust usually present in factory workshops.

A special problem is presented in the antistatic treatment of films, threads and fibers of polyolefins. It is known to those skilled in the art that, in order to obtain an antistatic effectiveness, it is important that the surface of the molded articles be coated with the antistat compound. This surface coating is considerably smaller in case of threads and fibers than in case of injectionmolded, extruded, and deep-drawn articles, after admixing the same amount by weight of antistat, due to the fact thatthe surface area of threads and fibers is very large as related to the weight thereof. Accordingly, it is to be expected that the effectiveness of an antistatic agent in threads and fibers commences only after uneconomically large amounts have been added thereto. Such a behavior is also usually observed.

Consequently, there is a special'need for antistatic agents which become effective in fibers already at'low amounts of addition. Especially valuable would be an agent of this type which protects,.in the same range of concentration, compact molded articles as well as fibers, so that it is possible to utilize the same molding composition for a great variety of manufacturing fields.

Alarge number of 2-fatty-alkyl oxazolines and imidazolines,-as well as the N-derivatives thereof, are described in the patent-literature. In contrast thereto, of

the tetrahydropyrimidines, there are disclosed only specific esters with other heterocyclic compounds, for

(US. Pat. Nos. 3,020,276 and 3,024,236). Copolymers of acrylic and vinylcompounds and N-vinyl tetrahydropyrimidines are also known. (Belgian Pat. 625,362). v

' A person skilled in the art had to conclude from this state of the art that only complicated tetrahydropyrimidines are effective, rather than the simple tetrahydropyrimidines, e.g.-, the Z-fatty-alkyl derivatives.

In general, the use of these additives have generally related to the antistatic treatment of molding compositions and shaped articles. The term shaped articles", as used herein means the products of the injection molding, extrusion and-deep-drawing processes, i.e., relatively compact articles, as" opposed to films, fila ments and fibers.

A special problem exists in the antistatic treatment of threads andfibers of polyolefins. In order to obtain full antistatic effectiveness, it is important, of course, that the total surface of the molded article is coated with the antistat. However, the surface coating achieved in the case of filaments and' fibers is considerably less when employing the same amount by weight of antistat,

due to the much higher surface area of filaments and .fibers, per unit weight, compared with injectionmote the dyeability, have the disadvantage that they produce only minor antistatic effects. Thus, the dyeability of polyolefin fibers and threads by complex dyes can be increased by' adding metallic salts or metallic complexes to the polyolefin prior to spinning. (See DAS 1,292,311 or German Unexamined Published Ap-' plication DOS 1,494,686). However, an additional disadvantage of this method is that the thus-obtained threads and fibers do not have an increased affinity to 1,422,396 or Japanese Pat. 4201/68). Another method consists of grafting these monomeric vinyl compounds onto the surface of the formed fibers. (See Japanese Pats.-8990/68 or 27 159/68). However, a simultaneous antistatic effect is not achieved with these compounds. It is also known that the dyeability of the polyolefin threads and fibers with acid dyes or dispersion dyes can be increased by incorporating into polyolefins basic condensation products of primary .and secondary amines or polyamines and epichlorohydrin or polyepoxides. (See French Pat. 1,367,387 or German Application DQS 1,469,105 or DOS 1,645,017). These basic condensation polymers exhibit an antistatic effect because of their polyether and polyamine units. However, this effect is minor, since the compounds, due to their polymeric structure, are unable to diffuse from the interior of the fiber to the fiber surface. Consequently, the largest portion thereof remains in the interior of the fiber so that only a minor percentage of that incorporated in the polymer composition is available to increase the conductivity of the fiber on the surface thereof.

Therefore, the problem exists, which has not been solved heretofore satisfactorily of producing polyolefin molding compositions and shaped articles of polyolefins which simultaneously possess a high dye affinity and a high antistatic effect.

In the copending application of Magosch, Rombusch and Eichers,'Ser. No. 84,886, filed Oct. 28, 1970, now

U.S. 3,701,765 there is claimed the use of tetrahydropyrimidines of the formula wherein R inter alkyl or alkenyl of 1-5 carbon atoms, and R is alkyl or alkenyl of 5-25 carbon atoms,

i.e., the compound contains both a long chain and a SUMMARY OF THE INVENTION According to this invention, polyolefins are rendered antistatic with the advantages described above by incorporating therein 0.1 -'5.0 percent by weight, based on the polyolefm, of one or more compounds of the formula:

wherein R, and R both are alkyl or alkenyl of 6-25 carbon atoms.

ETAI ED DISC SSION It is very surprising that by using tetrahydropyrimidines containing two long chain alkyl chains, threads and fibers of polyolefins simultaneously become both highly dyeable and antistatic. Heretofore, nitrogen bases with two long chain alkyl groups have been considered by those skilled in the art to be ineffective as antistats. Likewise, in view of the dilution" of the basic group in the molecule by the lengthening of the short alkyl chain, it was unexpected that the dyeability of the filaments and fibers, especailly with respect to acid dyestuffs, wouldalso be improved.

Polyolefins which can be rendered antistatic accord-' ing to this invention include highand low-pressure polymers of ethylene, propylene, butene-l, pentene-l,

etc., in particular all polyethylene types having 1 values of about 0.4 4.0, corresponding to average molecular weights of about 20,000 200,000; polypropylenes with 17 values of about 1.5 70, corresponding to average molecular weights of about 100,000 800,000; and polybutenes-1 .with rp values of about 1.0 6.0, corresponding to average molecular weights of about 500,000 3,000,000 and copolymers and polymer mixtures thereof. Preferred are isotactic polypropylenes with 17 values of 1.7 2.5, corresponding to average molecular weights of 150,000 300,000. Ofv the compounds of Formula I, preferred are those wherein R is an alkyl or alkenyl of 8-18, more preferably'lO-l4, carbon atoms, and R is alkyl or alkenyl of 7-17, preferably 9-13, carbon trimethylhexyl, n-decyl, n-undecyl, n-undecenyl, n-

dodecyl, n-tridecyl, n-tetradecyl, hexadecyl, octadecyl, octadece'nyl, eicosyl, doeicosyl and pentaeicosyl. Preferred are the octyl, decyl, dodecyl, tetradecyl and octadecyl. p Examples of such R groups are n-heptyl, 2- 'ethylpentyl, n-nonyl, n-undecyl, n-tridecyl, n-

heptadecyl, heptadecenyl, and heneicosyl residues. Preferred are heptyl, nonyl, undecyl, tridecyl and heptadecyl.

carboxylic acids or a derivative thereof, such as, e.g.,

an ester or nitrile. Advantageously, carboxylic acids and 1,3-propanediamines are used as the starting compounds and the thus-produced water (2 mols per mol of tetrahydropyrimidine) is removed azeotropically from the reaction mixture, xylene preferably being used as the azeotropic agent. In addition, a number of other manufacturing methods are known which, however, are not of commercial significance.

The amounts of the above-disclosed antistatic agents incorporated into the polyolefins range usually between 0.1 and 5.0 percent by weight, based on the polyolefin. Preferred are amounts from 0.5 to 4.0 percent by weight, since these amounts provide complete protection against dust accumulation by electrostatic attraction even in case of very dry and warm air, without appreciably impairing the crack resistance of the highly I crystalline types of polyolefins. 1f lower concentrations are employed, the protection against electrostatic charging is substantially lower. Such protection although insufficient for dry air, may still be sufficent when the polyolefin is stored in moist air. Higher concentrations'than 5.0 percent are normally unnecessary since they do not result in any further improvement in antistatic properties. The additive can be incorporated into the polyolefin in various ways. For example, the

' polyolefin and the mixture thoroughly stirred. The solvent can thereafter be removed, for example, by distillation. A solvent suitable for this purpose is methanol. Other readily distillable solvents can also be employed for this purpose.

A well proven method is to first produce a granulated polyolefin having a high concentration of tetrahydropyridmidine and then bringing this granulated com- I position to the desired tetrahydropyrimidine content during processing by admixing thereto additional granulated polyolefin which is free of that additive.

The novel antistatic polyolefin compositions can also contain, e.g., 0.01 3.0 percent by weight, based on the polyolefin, of other conventional antistats, such as, for example, polyethylene glycols and polypropylene glycols, polyols, e.g., glycerin and the monoethers and monoesters thereof, the diethers and diesters, and the ether-esters, and/or alkyl-amines and fatty acid amides, as well as other additives customary in filament and fiber production, e.g., dyestuffs, pigments, stabilizers, lubricants, plasticizers and fillers.

For example, there can be added to the polyolefin stabilizers which prevent the slight yellowing of the antistats which can occur upon the prolonged exposure to high temperatures, e.g., phosphites, preferably didecylphenylphosphite, triphenylphosphite, tris(nonylphenyl)phosphite and tris( nonylphenol 9 mols ethylene oxide) phosphite. These additives usually are added in amounts of about 0.01 0.4 percent by weight, calculated on the polyolefin. The addition of an alkanesulfonate, e.g., sodium pentadecanesulfonate, in an amount of about 0.1 2.0 percent by weight, calculated on the polyolefin, has the same advantageous effect. Likewise, UV-stabilizers can also be added.

The antistatic behavior of the threads and fibers is tested by the ash dusttesting method and by measuring the surface resistance according to'DIN 53 482 VDE 0303, Part 3. (In this test, means ash attraction, means no ash attraction). For further details thereof,

see Ser. No. 84,886, filed Oct. 28, 1970, now US. Pat. No. 3,701,765. These tests are conducted on small (10 g.) polyolefin strands wound off from the spinning bobbins.

In the following examples, the selected quantities of the claimied tetrahydropyrimidines are blended with 3 kg. of isotactic polypropylene powder having a relative viscosity of 2.0 (c 0.1 g. per ml. at C. in decaline). The thus-obtained powder is then granulated in an extruder. In the comparative examples, the same procedure is followed. The thus-obtained granulated material is spun into filaments in a melt spinning apparatus at 245295 C. by melting andextrusion through an S-hole spinncrette (diameter of the holes 0.25 mm.) These filaments are then wound onto bobbins. By means of melt-spinning, monoor polyfilaments can be produced which are further processed into continuous fibers or staple fibers, texturized yarns, or staple yarns.

The fibers are preferably drawn (oriented) after their manufacture, e.g., at a stretching ratio of 2:1 to 10:,1

and then wound onto bobbins. This drawing can be From the thus-obtained bobbins of drawn filaments, 10-

g. strands are wound off, and the surface resistance is measured with a tera-ohmmeter (produced by Kamphausen; electrode spacing 1 cm.) and the attraction of cigarette ashes thereto (ash dust test; height 0.5 cm. above the ash) afterrubbing with a cellulose rag (after 24 hours of storage at 23 C., 60 percent relative humidity).

' Employing the same testing method, the surface re sistance of the polyolefin threads and fibers is measured after being washed'once in household washing machines (gentle or boiling cycle) and after dyeing in a conventional dyeing process. 1

The novel polyolefin threads and fibers produced according to this invention with a tetrahydropyrimidine as defined herein incorporated therein, as manufactured as well as after washing or dyeing, have a surface resistance of s 10 MO and do not attract ashes in the ash test. ln'contrast thereto, corresponding polyolefin threads and fibers which do not contain the antistat, exhibit a surface resistance of 2 10 MO and strongly attract the ashes.

Fibers produced according to this invention likewise possess a remarkable affinity to acid dyes and dispersion dyes. A test dyeing step was conducted for 1 hour at 100 C. in dye baths containing 2 percent by weight o f coloring agent, based on the fiber, with a liquor ratio of 1:40. The test dyeings with the acid dyes were conducted in the presence of 2 percent of acetic acid (60 percent strength) and 5 percent of sodium sulfate.

The dyeings with the dispersion dyes were carried out in the presence of 2 percent of acetic acid (60 percent strength) and 1 percent of a levelling agent. After dyeing, the yarns were thoroughly rinsed and additionally cleaned with a monionic surfactant (1 g./l. at temperatures of 40-70 C.), in order to remove superficially bound dye.

In all cases, the yarns were intensively colored with the acid and dispersion dyes, whereas the corresponding polyolefin threads and fibers which lacked the antistat of the present invention, were dyed at most only to a very slight extent under the same dyeing conditions.

EXAMPLES 1-3 8 admixed to isotactic polyproplene powder having a relative viscosity of 2.0, the resulting powdered mixture is granulated, spun in the melt spinning plant under the conditions described for Examples 1-3, and then 5 drawn.

Drawing ratio 5 z 1 Drawing temperature Temperature of the iron cosity of 2.0, and the powdered mixture is granulated and spun in a melt spinning apparatus under the condi- The thus-produced filaments have the properties 40 shown in Table 1.

[pressing iron) 120 ln Examples 1-3. the selected amount of l-dodeeyl- I 2-nonyltetrahydropyrimidine (DNTHP) is added to The resulting filaments have the properties shown in 'isotactic polypropylene powder having a relative vis- Table II.

TABLE 11 Example 4 Example 5 Example 6 Example 7 DNTHP (7c 1 2 3 4 Titer (dtex) 42/8 44/8 41/8 4.5/8 Tensile elongation (7r) '47 36 41 45 tensile strength [p/dtex] 4.5 5.1 4.3 4.1

Surface resistance (M9) W.L. 7-10 4 10 110" 4 10* A.G.L. 1-10 7 10- 2-10 7-10 A.B.L. 9-10- 1-10 .2 10 910 A.D. 310;" 1-10 11-10 410* Dyestuff affinity Acilansaphirol SE 2 ,3 3 3 Dispersolechtorange" l 2 2 2 EXAMPLES 8-10 In Examples 8-10, the selected amount of l-dodecyl- 2-heptadecenyltetrahydropyrimidine (DHETHP) is admixed with isotactic polypropylene powder having a relative viscosity of 2.0; the powdered mixture is granu lated, spun by melt spinnning under the conditions described for Examples 1-3, and thereafter drawn.

Drawing ratio 5.2 1 Drawing temperature 120 C. Temperature of the iron 120 C.

Without laundering:

After boiling laundering (light detergent. 100 C.);

After dyeing The color no dye absorption slight dye absorption good dye absorption 0 1: 2: 3' very good dye absorption EXAMPLES 4-7 1N Examples 44. the selected amount of DNTHP is.

After gentle laundering (commercial alkane'sulfonate gentle detergent. C.)

depth was judged in accordance with the following scale:

The thus-produced filaments have the properties shown in Table III.

tetrahydropyrimidine,

Dispersolechtorangc TABLE COMPARATIVE EXAMPLES 15-18 Example Example EXampl-e' In Comparatiye Example 15, isotactic polypropylene 8 9 (relative viscosity 2.0) is employed without any addi- DHETHP (7) l 3 S tive, and in Comparative EXampIes 16-18 the samef 4H8 4-5/8 42/8 7 polypropylene is mixed with the indicated amounts of Tensile elongation (a) 55 58 62 PVP additive, spun under the conditions described for itirisg tlrc g s 4 4 I Examples 1-3, and thereafter drawn. Surface resistance (MO) I w t 3. :t 2 A f 8 :8, Z :8 Draw ng ratio: 5.4 i 'A'B H04 H03 9 02 Drawing temperature: 120 C. AD' 9,104 7 OJ Temperature of the iron: 120 C. Dyestuff affinity I I g g The resulting filaments have the properties shown in g Table v.

i TABLE v C0mpara- Compara- Compara- Comparai tive Extive Extive Extive Example l5 ample l6 ample l7 ample l8 PVP by weight) 0 1 3 '5 Titer (dtex) 51/8 54/8 50/8 47/8 Tensile elongation 49 59 54 54 (71) Tensile strength [p/dtex] 5.6 4.8 5.0 4.7 Surface resistance (Mn) W.L. 10 10 10 |0' A G,L. 10 10 l()' 10: A.B.L. 10 10 l0 10: A.D. l0=(+) 10 10(+) i0- Dyestuff affinity Acilansaphirol SE" 0 0 l l 0 l 2 2 Comparable results areobtainedwhen l-dodecyl-Z- undecyltetrahydropyrimidine, l -dodecyl-2-heptadecyl- COMPARATIVE EXAMPLES 1 114 In Comparative Example 11, isotactic polypropylene (relative viscosity 2.0) is employed without additive,

and in Comparative Examples 12-14, the same poly propylene is mixed with the indicated amounts of polyvinylpyridine (PVP), and spun under the conditions described for Examples 14-3. The resulting filaments have the properties shown in Table IV.

l-octadecyl-2-heptadecyltet- The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in-the preceding examples.

What is claimed is:

l. Antistatic and dyeable thermoplastic polyolefin.

compositions containing 0.1 5.0 percent by weight,

TABLE [V Compara- Compara- Compara- Comparative Extive Extive Extive Example l4 ample l3 ample l2 ample ll PVP (7: by weight) 0 l 3 5 Titer (dtex) 92/8 94/8 94/3 92/8 Tensile elongation (71) 4075 302 34] 337 tensile strength lp/dtex] L46 L12 -l.l L0 Surface resistance (M9) W.L. 10 10 10 l0' A.G.L l0(+) l0 l0(+) l0"(+) A.B.L. 10 10 10 l0 A D l0(+) l0 l0(+) 10 Dyestuff affinity Acilansaphirol SE" 0-l 0-] l. 1 v "Dispersolechtora'nge" 0 l 2 2 6 A 1 1 based on the polyolefin, of a compound of the formula N-OH:

4 1 fl/ wherein R and R each are alkyl or alkenyl of 6-25 carbon atoms.

2. A composition-of claim 8-l8carbon atoms.

3. A composition of claim 10-14 carbon atoms.

4. A composition of claim 7-17 carbon atoms.

"5. A composition of claim 9-13 carbon atoms.

6. A composition of claim 8-18 carbon atoms and R atoms.

7. A composition of claim 6 wherein R, contains 1014 carbon atoms and R contains 9-13 carbon atoms.

1 wherein R. contains 2 wherein R contains 1 wherein R 4 wherein R contains 1 wherein R contains contains 7-17 carbon contains 8. A composition according to claim 1 containing 1- dodecyl-2-nonyltetrahydropyrimidine.

9. A composition according to claim-l containing 1- dodecyl-2-heptadecenyltetrahydropyrimidine.

10. A composition according to claim 1 wherein the polyolefin is polypropylene.

11. A composition according to claim 1 in the form of filaments or fibers.

12. A composition according to claim 11 wherein the polyolefin is isotactic polypropylene.

13. A composition according to claim 12 wherein R, contains 8-l 8 carbon atoms and R contains 7-1 7 carbon atoms.'

14. A composition according to claim 13 wherein R contains l4 carbon atoms and R contains 9-l 3 carbon atoms.

, 15. A composition according to claim 12 containing,

l-dodecyl-2-nonyltetrahydropyrimidine.

16. A composition according to claim 12 containing 1-dodecyl-Z-heptadecenylte trahydropyrimidine. 

2. A composition of claim 1 wherein R1 contains 8-18carbon atoms.
 3. A composition of claim 2 wherein R1 contains 10-14 carbon atoms.
 4. A composition of claim 1 wherein R2 contains 7-17 carbon atoms.
 5. A composition of claim 4 wherein R2 contains 9-13 carbon atoms.
 6. A composition of claim 1 wherein R1 contains 8-18 carbon atoms and R2 contains 7-17 carbon atoms.
 7. A composition of claim 6 wherein R1 contains 10-14 carbon atoms and R2 contains 9-13 carbon atoms.
 8. A composition according to claim 1 containing 1-dodecyl-2-nonyltetrahydropyrimidine.
 9. A composition according to claim 1 containing 1-dodecyl-2-heptadecenyltetrahydropyrimidine.
 10. A composition according to claim 1 wherein the polyolefin is polypropylene.
 11. A composition according to claim 1 in the form of filaments or fibers.
 12. A composition according to claim 11 wherein the polyolefin is isotactic polypropylene.
 13. A composition according to claim 12 wherein R1 contains 8-18 carbon atoms and R2 contains 7-17 carbon atoms.
 14. A composition according to claim 13 wherein R1 contains 10-14 carbon atoms and R2 contains 9-13 carbon atoms.
 15. A composition according to claim 12 containing 1-dodecyl-2-nonyltetrahydropyrimidine.
 16. A composition according to claim 12 containing 1-dodecyl-2-heptadecenyltetrahydropyrimidine. 